cereus

Cereus is a genus of cacti in the family Cactaceae that includes several tall, columnar species native to the Americas. They occur in arid and semi-arid regions of South America, Central America, the Caribbean, and nearby areas, often on rocky slopes or open scrubland. Most Cereus forms are erect or may branch after injury, with stems that are ribbed and spiny; spine length and density vary among species.

Flowers are typically large and nocturnal, often funnel-shaped and white or pale. They open at night and are usually pollinated by bats or nocturnal moths. Fruits are berry-like and may be edible in some species, though culinary value varies and some fruits are consumed locally.

In cultivation, cereus species are valued as ornamental cacti in warm climates and in greenhouses. They prefer full sun, well-draining soil, and relatively sparse irrigation, with more water during the growing season and protection from frost in temperate regions. Propagation is commonly accomplished by cuttings or seeds.

Taxonomically, Cereus has undergone revisions, with some former members reassigned to related genera as classification has advanced. The genus is characterized by its tall, columnar habit and nocturnal flowers adapted to pollination by nocturnal visitors.